Charging means for transit mixers



Oct. 17, 1944. 1.. G. HILKEMEIER CHARGING MEANS FOR TRANSIT MIXERS Filed April 18, 1942 2 Sheets-Sheet l Louis Gfiilkemeier INVENTOR.

ATTORNEY.

Oct. 17, 1944. L. HlLKEMElER 2,360,345

CHARGING MEANS FOR TRANSIT MIXERS Filed April 18, 1942 2 Sheets-Sheet 2 'IITIJ IIIIIIIA INVENTOR.

BY WV z AT TORNE YT Patented Oct. 17, 1944 UNITED STATES PATENT OFFIC CHARGING MEANS FOR TRANSIT MIXERS Louis G. Hilkemeicr, West Allis, Wis., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application April 18, 1942, Serial No. 439,461

/ 16 Claims.

This invention relates to concrete mixers and particularly to charging instrumentalities therefor. One especially useful adaption of the invention is in the field of transit concrete mixers of the type which employ a mixing drum mounted for rotation about an inclined axis with an axial opening at the higher end of the drum for receiving the ingredients of a concrete mixture and through which the mixed concrete is discharged.

One of the principal objects of the present invention is to provide a charging device so mounted with respect to the frame of the mixer that misalignment between the drum and the charging device, such as is produced by uneven road conditions, may be materially reduced and the charging means restrained against rotation while held in sealed, bearing contact with the rotating drum.

Another object of the invention is to provide means for charging such mixers which enables utilization of the entire drum opening to promote rapid passage of material into the drum, while at the same time, providing a durable structure in which excessive wear of parts may be prevented.

A still further object is to provide means for insuring proper lubrication of wearing parts so as to require less service attention.

These and other objects are acccomplished by a unique arrangement of charging hopper and associated elements, two embodiments of the invention being illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation, partly in section showing the rear portion of the mixer drum with the charging device associated therewith;

Fig. 2' is a section taken on line 2--2 of Fig. 1;

Fig. 3 is an enlarged section of the bearing and seal between the charging device and the drum;

Fig. 4 is a. section showing a modified form of bearing; and

Fig. 5 is another sectional view of the bearing shown in Fig. 3 illustrating the greasing connection.

In the drawings, the mixer drum H, only one end portion of which is shown, is preferably of the type mounted for rotation about an inclined axis, the higher end of which is provided with an axial opening l2 through which the materials may pass into and out of the drum. The method of mounting the drum is not shown as it forms no part of this invention, it being understood that the drum is supported rotatably in a frame, a very desirable type of which is box-like in shape with rear up-right member 13 set at right angles to the axis of rotation of the drum. With this wardly and support as a saddle the upper portion of a hopper l8,'so as to enable swinging movement of the hopper to and from a position contiguous with the drum opening. For guiding the movement of the hopper and supplying pressure to its lower portion there are a pair of depending arms I9 secured to pivot rod l5, said rods l9 having at their lower extremities a resilient connection to trunnions 20 mounted on the sides of the hopper. Trunnions 20 are preferably disposed at right angles to the drum axis and as radii therefrom, thereby distributing the forces applied to the hopper to cause it to seat evenly against the drum.

In order to provide a yielding connection between trunnions 20 and depending arms IS, a relatively short link 2| is pinned to each arm l9, and this link 2| houses one end of a reciprocating member 22, the other end of said member having an eye portion 23 journalled on trunnion 20. The end of member 22 housed in link 2| has a rim 24 which serves as a shoulder to retain a coil spring 25 bearing against the other, inner side of the link housing. In this manner pressure applied on either side of the hopper may, through the medium of compressible springs 25, be equalized, and also proper seating of the hopper accomplished through the provision of pivoting arms H) which are supplemental to the rigid connection at the top of the hopper.

. For actuating the hopper and swinging it away from the vdrum opening, so as to permit discharge of mixed concrete, pivot rod I5 is secured to an operating arm 26, the latter being connected to crank arm 21 through the medium of a connecting link 28. Any suitable means of operating the crank arm 21 may be employed including Without limitation either a hand wheel and worm, or hydraulic means. Since these means form no part of the present invention and are well known in the art, it is not deemed necessary that they be illustrated in the drawings.

The drum opening I2 is provided with a cylindrical flange 28 affording a plane surface at right angles to the axis of rotation to the drum. Disposed between this surface and the lower, an-

'said packing lying against the face 31.

nular portion of the hopper is an intermediate ring or yoke 29. the inner diameter of which is slightly smaller than the lower or discharge opening of hopper It so as to be engaged thereby when the hopper is in charging position. In order to provide better seating contact between the hopper and the ring-like member 29, an annular groove 39 is provided in the lower portion of the hopper and a ring 3| of hard, wear-resisting material, is securely lodged in the groove. The outer diameter of annular member 29 is slightly greater than the drum opening and is retained by the drum through a bearing and sealing arrangement which will be more particularly described hereinafter.

At either side of annular member 29, there is an ear 32 which extends substantially radially and horizontally from the drum axis, which car is retained in a U shaped collar 33 mounted on a bracket 34 extending rearwardly from the upright member l3 of the mixer frame. By this arrangement, rotation of the annular ring 29 is prevented by collar 33, although the ring is free to move axially with respect to the drum, and also to be removed from the drum if occasion demands.

Between annular ring-shaped member 29, and flange 28' at the end of the drum, it is necessary to provide a bearing since the drum rotates and the ring is held stationary. In the drawings, two types of bearings suitable for this purpose are illustrated, the type shown in Fig. 1, having the advantage that a seal is also provided to protect the bearing from material worked through the drum opening.

With the bearing shown in Fig. 1, there is secured to annular member 29, a rim member 35, which is L shaped in cross section, having one face which is radial as at 35 and is secured to annular member 29, whereas the other face 31 is cylindrical with respect to the drum axis. This assembly is retained by a third ring 38, which is mounted on studs 39 secured to the end of the drum, these studs also retaining a replaceable bearing member 49- which is adapted to contact the radial face 36 of rim 35. A suitable spring-pressed packing member 40 may be inserted into an annular groove in member 40,

Bearing member 40 is held in spaced relation away from the drum opening by spacer sleeves 4| mounted on studs 39, and the studs are spaced angularly so as to provide gaps for the escape of materialto the ground. To more fully protect the bearing a sealing ring 42 which is generally U shaped in cross section is mounted on the outer side of cylindrical face 31 of rim 35, said ring 42 being disposed inwardly of the bearing member 40; and the legs 43 of the U shaped ring 42 are adapted to press against the cylindrical flange 28' which is secured to the opening of the drum. This arrangement is more fully described in my copending application Serial No. 428,603 flied Jan. 28, 1942.

In Fig. 4, a somewhat modified form of bearing is disclosed, in which the drum flange 29 is so shaped as to afford a somewhat larger radial surface area and there is secured to the inner side of annular member 29, a ring like hearing member 44 having an insert packing which contacts the outer radial face of drum flange 28'. Thi bearing member 44, which may be secured to the annular member by a number of set screws 45, has a slightly larger outer radius than annular member 29, whereby the extended portion of the bearing may be retained by a series of clips 49 bolted to the flange 23'.

With either form of bearing the retaining means, such as the studs 39. secured to the drum, prevent the intermediate bearing member 29 from sliding out of collars 33, when the hopper is swung into discharge position. Consequently bearing member 29 is in eilect mounted on the end of the drum, but it is restrained against rotation by ears 32 and collars 33, and it is held in bearing contact with the drum through pressure exerted by the hopper. Since neither the hopper nor the bearing member can rotate, there is no frictional contact between them, nor can excessive wear result because of misalignment of the hopper through distortions of the frame caused by road conditions. Also mounted on bearing member 29 is a small spout or sub-. chute 41 for receiving concrete as it is discharged through the drum opening, it being understood that chute 41 must be large enough to catch the material discharged from the side as well as the bottom of the drum opening, and must also permit clearance for the swinging movement of the hopper as herebefore described.

In order to provide lubricant for the seal, such as is shown in Fig. 1, there is provided 'one or more grease fittings 48, communicating with the space between the legs 43 of the U shaped sealing member 42 by means of an opening provided in rim 35. This fitting is connected through a tube or hose 49 with a grease reservoir 59, and provision is made for automatically feeding grease into the seal each time the hopper is moved from discharge into charging position. To accomplish such action, the outlet of the reservoir is provided with a port 5| leading into a cylinder 52, in which a plunger 53 is mounted for reciprocating movement, and one end of the cylinder is provided with an opening to which a T shaped fitting 54 is attached, said fitting housing a small one-way valve 55 permitting passage of grease into tube 49, which communicates with the seal. The other end of cylinder 52 is provided with a packing 55 through which the plunger extends, the extended portion being pinned to a link 51. which is operated by an arm 58, rigidly connected to link 25 of the hopper actuating mechanism. Port 5| is suillciently removed from the forward end of plunger 53, when the latter is in its most forward position, to prevent operation of the lubricating means unless the hopper is swung a considerable distance. In this manner needless waste of grease is prevented, such as might occur if each slight movement of the hopper would cause operation of the greasing system. There is also some lost motion in the connection between arm 58 and link 51 to accommodate permissible movement of the hopper, and the lost motion connection is such as to permit ready detachment and separate manual operation of the plunger if desired.

The grease reservoir, which may be mounted on any convenient portion of the mixer frame, is provided with a cover 59, secured by means of a bayonet joint, and pressure is maintained on the entire surface of the grease to prevent it from channelling to the port 5| as it might otherwise do in cold weather.

The operation of the greasing system is as follows: When the hopper is swung into open position, movement of the hopper actuating arm causes piston 53 to be retracted, thus establishing a vacuum and closing valve 55, thereby causing grease in the reservoir to be drawn through port into cylinder 52. Subsequently, upon return of the hopper to its charging position, piston 53 is caused to move to the left, as seen on the drawings, forcing grease past valve 55 into conduit 49. The length of chambe 52 and the disposition of port 5| is such that suflicient quantity of grease is expelled on each complete movement of the plunger to adequately grease the hopper seal.

Once the grease reaches seal 42, it will pass around the circumferential groove formed by the legs 43 of the seal, thus effectively lubricating the entire contacting surface between the seal and the drum. Since the shape of seal 42 is such that grease working through the seal will tend to enter the charging passage (due to deflection of the leg members 43 when in contact with the drum), it is practically impossible for concrete to work its way out past the seal. And furthermore any concrete which enters this space is inhibited from setting by the presence of an adequate supply of inhibiting material in the seal.

While the lubricating system just described is not illustrated in conjunction with the other type of bearing and seal, as shown in Fig. 4, it will be clear to those skilled in the art that the same system may be employed to insure automatic lubrication of this other type of bearing and seal after each discharging operation. In this arrangement, a grease fitting may conveniently be employed where cap screw 45 is employed, supplying lubricant to the space between flange 28 and bearing member 44.

Referring again to the hopper and bearing structure, the arrangement is such that upon movement of the pivot rod by the actuating mechanism, hopper I 8 is swung by the arms I! which pivotally connect the upper portion of the hopper to the pivot rod. As the hopper is swung down into charging position, arms l9, yieldably connected to the lower portion of the hopper, cause pressure to be applied against annular member 29 and force it into bearing engagement with the end of the drum. By means of trunnions 32 on ring 29 and brackets 34 mounted on the mixe frame, annular member 29 is restrained against rotation, but limited axial movement is permitted to cause the bearing to engage the drum. In this manner, a floating bearing is formed, supported on the drum, said bearing being held against rotation and enabling the hopper to maintain contact therewith which, since it is a non-rotational contact, cannot produce excessive wear because of distortions of the mixer frame and hopper, produced by road conditions.

Finally when it is desired to discharge the drum, the hopper, which constitutes means when in charging position retaining materials in the drum, is removed and space is provided for discharge of the contents of the drum. During this operation, the bearing member 29 is retained by the guideway formed on the end of the drum by ring 38' or as shown in the modified form by clips 46, and the concrete conveyed to the drum opening by the mixing blades within the drum is passed through the opening and received in chute 41. During this last operation, with the type of bearing shown in Fig. 4, it may well be desirable to provide resilient connectin means to maintain the yoke 44 in axial tension against the drum when the hopper is retracted into discharge position.

Since the method of supporting and actuating the hopper is entirely external to the passageway through the hopper, the time required for charging is relatively short, for the hopper communicates with the entire space provided by the drum opening.

Where used in the claims, the term lubricant is not intended to be limited to any particular material, such as grease, but it is intended to cover all equivalents which have the property of inhibiting the setting of concrete or lubricating the contacting surfaces.

The invention having been described what is claimed is:

1. Charging .instrumentalities for concrete mixers having a rotatable mixing drum with an axial opening at one end and bearing surface surrounding said opening, said instrumentalities comprising a charging hopper maintained in upright position during charging operations, pressural means urging said hopper toward said drum opening, a bearing member arranged between said hopper and said drum, said member being disposed to transmit pressure exerted on said hopper and to have bearin contact with the bearing surface, and means preventing rotation of said bearing member.

2. In a concrete mixer, a frame, a rotatable mixing drum having an axially arranged opening at one end and a flange surrounding said opening, a charging hopper, an annular member disposed between said hopper and the drum flange, means mounted on the mixer frame locking said annular member against rotation but permitting limited axial movement thereof, and means exerting axial pressure on said hopper to cause bearing contact between said member and the drum flange while the member is locked against rotation and in sealed engagement with the hopper.

3. In a concrete mixer, a frame, a mixing drum mounted for rotation while supported on said frame, said drum having an axial opening and a flange surrounding said opening, a charging hopper, an annular member disposed to engage said drum flange in bearing relation thereto, said annular member having trunnions extending radially outwardly from its periphery, brackets mounted on said frame having elongated slots disposed to enclose said trunnions and permit limited movement of said member axially with respect to said drum and pressural means urging said hopper against said annular member for maintaining non-rotational engagement therebetween, said pressural means maintaining bearing engagementbetween said annular member and the drum flange.

4. In a concrete mixer, a frame, a rotatable mixing drum supported by said frame and having an axial charging and discharging opening, a charging hopper pivotally mounted on said frame and yieldably tensioned against said drum when in charging position, a yoke supported by said drum and held against rotation while free to movein an axial direction with respect to said drum, said yoke being arranged between said hopper and said drum and transmitting pressure from said hopper against said drum, means retaining said yoke whennot under pressural engagement with said hopper, and a chute mounted on said yoke for receiving concrete discharged from said drum when said hopper is pivoted clear of said opening.

5. In a concrete mixer having a rotatable mixing drum with an axially disposed opening at one end and a charging hopper for charging materials through said opening, said hopper being retractable into a position clear of said opening for discharging mixed concrete, a bearing member disposed between said hopper and said drum,

a lubricant reservoir communicating with the said bearing member, and means controlled by movement of said hopper for supplying lubricant from said reservoir to said bearing member.

6. In a concrete mixer having a rotatable mixing drum and an axially disposed opening at one end for discharging concrete, 9. materials-retaining device cooperating with said opening and having one portion forming a bearing with said drum opening and another portion movablefrom a position in which the materials are retained into a position remote from said opening to enable discharge of the concrete, a source of lubricant supply communicating with the bearing portion of said device, and means controlled by movement of said other portion for effecting lubrication of said bearing portion at intervals not less than between discharge of each batch.

7. In a concrete mixer having a. rotatable mixing drum and an axially disposed opening at one end, a materials-retaining device comprising a bearing member surrounding said opening but held against rotation with said drum, means movable from a position enabling discharge through said bearing member, to a position in which pressural contact may be maintained against said bearing member, and means controlled by movement of said last named means for supplying lubricant to said bearing member.

8. In a concrete mixer: a frame, a rotatable drum having an opening at one end, a charging hopper, means supporting the hopper adjacent said opening, means mounted on the drum forming an annular guideway, a bearing member rotatable in said guideway and engageable with said charging hopper, means mounted on the frame restraining said bearing member against rotation and means effecting pressural contact between said hopper, said bearing and said drum.

9. In a concrete mixer having a rotatable mixing drum and an axially disposed opening at one end for receiving and discharging materials, a charging hopper engageable with the end of said drum for facilitating charging of materials through said opening, means restraining said charging hopper against rotation, means eil'ecting retraction of said hopper to permit discharge of mixed concrete, means actuated by said last named means for supplying lubricant to the friction areas between said hopper and said drum, said lubricant supplying means including a lost motion connection whereby substantial retraction of said hopper is required before said lubricating function operates.

10. In a concrete mixer, a rotatable mixing drum having an axially disposed, end-charging opening, a charging hopper having an annular lower portion, a floating bearing supported on the drum but restrained against rotation therewith, said bearing being disposed between said hopper and said drum, means for moving said hopper from a position remote from said opening to a position in contact with said bearing, and means controlled by movement of said last named means for effecting supply of lubricant to said bearing,

11. In a concrete mixer; a frame, a rotatable drum mounted on said frame and having an axial opening at one end, an annular guideway surrounding said opening and forming a bearing race, a rotatable bearing member disposed in said guideway, a charging hopper pivotally mounted on said frame and movable from a position contacting said bearing member to enable charging from said member to enable discharge and means mounted on the frame restraining rotation of said bearing member and insuring non-rotational relationship between the bearing member and the charging hopper.

12. In a concrete mixer having a frame and a rotatable mixing drum mounted thereon, said said drum and retained in said annular guideway, and means maintaining non-rotational engagement between the hopper and the bearing member when the hopper is in charging position.

13. In a concrete mixer; a frame, a rotatable mixing drum mounted on the frame and having an opening at one end, an annular guideway surrounding said opening and forming a bearing race, a rotatable bearing member disposed in said guideway, a charging hopper movably mounted on said frame and retractable from a position engaging said bearing member to a position remote therefrom, whereby discharge of the drum contents may be eifectuated through said opening, means restraining rotation of the bearing member whether in contact with the hopper or not, and a seal disposed between the bearing member and the drum opening shielding the bearing from the entrance of material passing through the opening.

14. In combination with a rotatable mixing drum having an axial opening at one end for admission of materials, said drum having an annular guideway surrounding said opening and forming a bearing race, a bearing member disposed in said guideway and restrained against rotation with said drum, said member having a face disposed radially of the drum axis and out of contact with the drum, a charging hopper having a lower, annular portion engageable with said face, and resilient mounting means for the hopper to insure sealing contact between the bearing member and the hopper.

15. In a concrete mixer, a rotatable mixing drum having an axially disposed, end-charging opening, a charging hopper having an annular lower portion, said hopper being movable from a position adjacent said opening to facilitate charging of materials into the drum to a position removed from said opening to permit discharge of materials from the drum, an annular member mounted on the drum restrained from axial disengagement with the drum and closing the space between the lower portion of the hopper and the drum opening when the hopper is in charging position, said annular member having a surface making bearing contact with the end of the drum, means for moving said hopper to and from a position contiguous to said annular member, and a positive lock maintaining said annular member against rotation with said drum.

16. In a concrete mixer having a rotatable mixing drum with an axially disposed opening at one end and an annular element surrounding said through said opening to another position removed opening, a chargin element held against rot tion with the drum and movable from a position adjacent to said opening to enable charging materials into the drum to a position removed therefrom to enable discharge. of materials from the drum, an intermediate, annular member disposed between the charging element and the annular element surrounding the opening of the drum and mounted on one of said elements, said intermediate member being rotatable with respect to the element on which it is mounted and having a bearing surface for engagement therewith, and means independent of friction engagement between said member and the other element for positively preventing relative rotation therebetween and insuring relative rotation at said bearing surface.

LOUIS G. HILKEMEIER. 

